Stockfish, a UCI chess playing engine derived from Glaurung 2.1
Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
+ Copyright (C) 2015-2020 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
Stockfish is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#ifndef SEARCH_H_INCLUDED
#define SEARCH_H_INCLUDED
-#include <atomic>
-#include <memory> // For std::unique_ptr
-#include <stack>
#include <vector>
#include "misc.h"
-#include "position.h"
+#include "movepick.h"
#include "types.h"
+class Position;
+
namespace Search {
+/// Threshold used for countermoves based pruning
+constexpr int CounterMovePruneThreshold = 0;
+
+
/// Stack struct keeps track of the information we need to remember from nodes
/// shallower and deeper in the tree during the search. Each search thread has
/// its own array of Stack objects, indexed by the current ply.
struct Stack {
Move* pv;
+ PieceToHistory* continuationHistory;
int ply;
Move currentMove;
Move excludedMove;
Move killers[2];
- Depth reduction;
Value staticEval;
- bool skipEarlyPruning;
+ int statScore;
int moveCount;
+ bool inCheck;
};
+
/// RootMove struct is used for moves at the root of the tree. For each root move
/// we store a score and a PV (really a refutation in the case of moves which
/// fail low). Score is normally set at -VALUE_INFINITE for all non-pv moves.
struct RootMove {
explicit RootMove(Move m) : pv(1, m) {}
-
- bool operator<(const RootMove& m) const { return m.score < score; } // Descending sort
- bool operator==(const Move& m) const { return pv[0] == m; }
- void insert_pv_in_tt(Position& pos);
bool extract_ponder_from_tt(Position& pos);
+ bool operator==(const Move& m) const { return pv[0] == m; }
+ bool operator<(const RootMove& m) const { // Sort in descending order
+ return m.score != score ? m.score < score
+ : m.previousScore < previousScore;
+ }
Value score = -VALUE_INFINITE;
Value previousScore = -VALUE_INFINITE;
+ int selDepth = 0;
+ int tbRank = 0;
+ int bestMoveCount = 0;
+ Value tbScore;
std::vector<Move> pv;
};
-typedef std::vector<RootMove> RootMoveVector;
+typedef std::vector<RootMove> RootMoves;
+
/// LimitsType struct stores information sent by GUI about available time to
-/// search the current move, maximum depth/time, if we are in analysis mode or
-/// if we have to ponder while it's our opponent's turn to move.
+/// search the current move, maximum depth/time, or if we are in analysis mode.
struct LimitsType {
LimitsType() { // Init explicitly due to broken value-initialization of non POD in MSVC
- nodes = time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movestogo =
- depth = movetime = mate = infinite = ponder = 0;
+ time[WHITE] = time[BLACK] = inc[WHITE] = inc[BLACK] = npmsec = movetime = TimePoint(0);
+ movestogo = depth = mate = perft = infinite = 0;
+ nodes = 0;
}
bool use_time_management() const {
- return !(mate | movetime | depth | nodes | infinite);
+ return !(mate | movetime | depth | nodes | perft | infinite);
}
std::vector<Move> searchmoves;
- int time[COLOR_NB], inc[COLOR_NB], npmsec, movestogo, depth, movetime, mate, infinite, ponder;
+ TimePoint time[COLOR_NB], inc[COLOR_NB], npmsec, movetime, startTime;
+ int movestogo, depth, mate, perft, infinite;
int64_t nodes;
- TimePoint startTime;
-};
-
-/// The SignalsType struct stores atomic flags updated during the search
-/// typically in an async fashion e.g. to stop the search by the GUI.
-
-struct SignalsType {
- std::atomic_bool stop, stopOnPonderhit;
};
-typedef std::unique_ptr<std::stack<StateInfo>> StateStackPtr;
-
-extern SignalsType Signals;
extern LimitsType Limits;
-extern StateStackPtr SetupStates;
void init();
void clear();
-template<bool Root = true> uint64_t perft(Position& pos, Depth depth);
} // namespace Search